DE 40 18 543 C1 discloses a tool turret having a housing to be connected to the machine tool. The housing has an electric drive motor and a tool disk mounted rotatably relative to the housing. The tool disc has recesses for machining tools, at least one of which is configured for rotatable mounting of the tool. The machining tool may be driven by the drive motor by shafts which are interconnected by gearing. A hollow column is mounted concentrically with the axis of rotation of the tool disk, and has at least one line included in a system provided for transmission of energy, lubricant, coolant, pressure means, or auxiliary forms of energy. The hollow column is immobile relative to the housing. One of the shafts driven by the drive motor is mounted in the hollow column and connected by the gearing to the other shaft by way of which the rotatably mounted tool may be driven when the recess into which this tool is introduced is in the operating position.
This tool turret permits transmitting the auxiliary forms of energy or auxiliary means to the tool modules, tools, or the tools requiring such forms of energy, in a space conserving, problem-free, simple, and cost-effective manner. However, in that the drive system involves shafts and gearing, the tool drive configuration still requires much structural space. Because of the large number of elements, the drive system is also subject to wear, is correspondingly cost intensive in production, and requires a certain degree of maintenance.
DE 39 00 443 A1 discloses a variable-angle packaged unit for machine tools including turret heads. Fixable cutters are retained in recesses mounted pivotably about a stationary table element along a longitudinal axis. Two table elements of the turret head are mounted pivotably relative to each other around the longitudinal axis by an electric drive integrated into the tool disk. Appropriate gearing down for the rotatable table element by way of a planet gear unit is possible. Driving of rotating machine tools is not possible.
DE 39 04 631 A1 discloses another turret head solution for machine tools, for turning machines in particular. An insertible rotating machine tool is driven by gearing and the drive shaft for the machine tool extending parallel to the main drive shaft for the turret head. The turret head is in the form of a tool disk. The central electric drive is positioned outside the table unit of the tool disk, so that a compact structure is not possible. In addition, since the electric drive is separated by a large axial distance from the tool disk driven by it together with the respective machining tool, inaccuracies in control of the structural components (disk, tool) are not excluded.